Alan Cox wrote:>> It implies clock tuning in userspace for a potential sub microsecond>> accurate clock. The clock accuracy will be limited by user space>> latencies and noise. You wont be able to discipline the system clock>> accurately.> > Noise matters, latency doesn't.

Well put! That's why we need hardware support for PTP timestamping to reduce the noise, but get along well with the clock servo that is steering the PHC in user space.